"Anne Hathaway is my kryptonite," Clarkson said ... if you know my catalogue at all — 'cause I don't — I thought I was singing Christina Aguilera's song 'Fighter,' and I was singing mine ...

She starts off by telling Hathaway that she will be singing her questions, in hopes that the Fantine actress would sing back. This led Hathaway to respond, "Well I won't be doing that but you're ...

"Anne Hathaway is never invited back ... if you know my catalogue at all — 'cause I don't — I thought I was singing Christina Aguilera's song "Fighter," and I was singing mine," she said.